yes she probably needs worming if it hasn't been done since may! Equimax is a good al round wormer which also treats for tapeworm. spring and autumn are the times to treat for tapeworm so I'd choose this wormer. check the box I think the horse needs worming again after 10wks. for the next one I'd use either Equest or Panacur Guard which is a 5-day course. both of these treat for encysted small red worm, which hibernate in the gut all winter then emerge together in the spring and can cause diarrhoea, colic or death. you worm for encysted redworm after the first frost(eg about november time or a bit later) and maybe again in the spring if you suspect a serious worm problem. Generally worming needs to be done every 8-13wks depending on the wormer used, check the box for instructions. apart from tapeworm and encysted redworm make sure you use a different ingredient each year for the other worming sessions, not just a different brand name you must actually check the box for the active ingredient. eg one ingredient on year one (with tapeworm and encysted redworm treatments), another ingredient on year two, another ingredient on year three, then on year four go back to year ones ingredient. if you need further advice consult your vet.